Lewis Hamilton’s X44 team topped qualifying at the first round of Extreme E.
France's nine-times world rally champion Sebastien Loeb and Spanish team mate Cristina Gutierrez led the way for the seven- times Formula One world champion's X44 outfit over the rock-strewn tracks and desert dunes.
Rosberg X Racing, run by the retired 2016 F1 world champion and Hamilton's former Mercedes team mate, would have been fastest but picked up a penalty for speeding in the driver switch zone.
Rosberg and Hamilton teams clash in Extreme E's Senegal round
Teams have only one car, with a male and female driver doing a lap each.
The penalty dropped Sweden's triple world rallycross champion Johan Kristoffersson and Australian rally driver Molly Taylor to third.
Three-times Dakar winner and double world rally champion Carlos Sainz qualified in second place with Spanish team mate and regular motorcycle rider Laia Sanz.
"The old former duel between the Rosberg team and Hamilton's team seems to be pretty hot," former F1 driver David Coulthard said.
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Rosberg, who unlike Hamilton was on site to watch the series' debut, said there had been a problem with the speed limiter.
Only six of the nine teams ran in second qualifying with Veloce pulling out of the event altogether due to car damage caused by French driver Stephane Sarrazin crashing heavily.
That withdrawal came as a blow for British team mate Jamie Chadwick, winner of the first all-female W Series, who had yet to run.
The JBXE team entered by 2009 F1 champion Jenson Button, who is also competing, were sixth fastest.
The brainchild of Formula E founder Alejandro Agag, Extreme E aims to highlight climate change and promote sustainability by racing in remote parts of the world affected by global warming and environmental damage.
There are five rounds ranging from locations in the Arctic to the Amazon
Extreme E: Button launches his car and team ahead of new series
Extreme E qualifying: Loeb, Gutierrez top the timesheets
Highlights: Rosberg's team are Extreme E's first race winners